The present invention generally relates to a universal joint for use in a driveline of a motor vehicle. More specifically, the present invention pertains to a universal joint equipped with a mechanism for securing a bearing cup assembly to a cruciform trunnion.
As is commonly known, universal joints are used in motor vehicle driveline applications for interconnecting a pair of rotary shafts and permitting changes in angularity therebetween. Many conventional universal joints include a pair of bifurcated yokes which are secured to the rotary shafts. The bifurcated yokes are interconnected by a spider or a cruciform for rotation about independent axes. The cruciform includes four orthogonal trunnions with each opposing pair of axially aligned trunnions mounted in a pair of aligned bores formed in the bifurcated yokes. Typically, a bearing cup is secured in each bore and a bearing assembly is retained in the bearing cup such that each yoke is supported for pivotal movement relative to one of the pairs of trunnions. In addition, it is known to use a thrust washer between the trunnion and the bearing cup to absorb the radially-directed thrust forces which may occur therebetween.
During assembly of the universal joint, difficulties may arise when attempting to couple the bearing assemblies to the cruciform. Typically, each bearing assembly includes a seal coupled to a bearing cup which engages a portion of the trunnion. During the assembly process, air and grease are sometimes trapped within the bearing cup. The pressure can cause the bearing assembly to be misaligned or to become improperly positioned after the installation force is removed. Possible bearing contamination and loss of productivity may result. In some instances, the bearing cup assemblies must be removed and re-installed requiring expense of time and cost. Accordingly, it would be advantageous to provide a universal joint having bearing cup assemblies which allow trapped air and grease to be purged during installation without compromising the integrity of the bearing cup to trunnion seal.
The present invention is directed to a universal joint for interconnecting a pair of rotating shafts. The universal joint includes a pair of bifurcated yokes interconnected by a cruciform. The cruciform includes four orthogonal trunnions each including a lubricant passage. A seal includes a plurality of protrusions engaging a portion of the trunnion to provide a purging path for trapped air.